package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.TransactionUsageException;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;


/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;


    @Resource
    private RedisIdWorker redisIdWorker;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();
    @PostConstruct
    public void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
    private class VoucherOrderHandler implements Runnable {

        @Override
        public void run() {
            while (true){
                try {
                    String queuName= "stream.orders";
                    //获取消息队列中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queuName, ReadOffset.lastConsumed())
                    );
                    //判断消息是否获取成功
                    if(list== null || list.isEmpty()){
                        continue;
                    }
                    //解析消息订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //获取成功，下单
                    handleVoucherOrder(voucherOrder);
                    //ACK确认

                    stringRedisTemplate.opsForStream().acknowledge(queuName,"g1", record.getId());
                }
                catch (Exception e) {
                    log.error("处理订单异常", e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while (true) {
                try {
                    String queuName= "stream.orders";
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queuName, ReadOffset.from("0"))
                    );
                    //判断消息是否获取成功
                    if(list== null || list.isEmpty()){
                        break;
                    }
                    //解析消息订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                }
                catch (Exception e) {
                    log.error("处理订单异常", e);
                    try {
                        Thread.sleep(200);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }
            }
        }
    }
    /*private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
    private class VoucherOrderHandler implements Runnable {
        @Override
        public void run() {
    while (true){
        try {
            //获取队列中的订单信息
            VoucherOrder voucherOrder = orderTasks.take();
            handleVoucherOrder(voucherOrder);
        } catch (Exception e) {
            log.error("处理订单异常", e);
        }
    }
        }
    }*/

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        //SimpleRedisLock lock = new SimpleRedisLock("order" + userId, stringRedisTemplate);
        RLock lock = redissonClient.getLock("lock:order:"+userId);
        boolean isLock = lock.tryLock();
        if (!isLock) {
            // 获取锁失败，直接返回失败或者重试
            log.error("不允许重复下单");
            return;
        }

        //获取代理对象（避免事务失效）
        try {

             proxy.createVoucherOrder(voucherOrder);

        }  finally {
            lock.unlock();
        }
    }
private IVoucherOrderService proxy;
    @Override
    @Transactional()

    public Result seckillVoucher(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        Long orderId = redisIdWorker.nextId("order");
        //执行seckill.lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString(),
                String.valueOf(orderId)
        );
        // 判断结果是否为0
        if (result.intValue() != 0) {
            // 不为0，代表没有购买资格
            return Result.fail(result.intValue() == 1 ? "库存不足" : "不能重复下单");
        }
        // 获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        return Result.ok(orderId);
    }

    public void createVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        Long voucherId = voucherOrder.getVoucherId();
        // 创建锁对象
        RLock redisLock = redissonClient.getLock("lock:order:" + userId);
        // 尝试获取锁
        boolean isLock = redisLock.tryLock();
        // 判断
        if (!isLock) {
            // 获取锁失败，直接返回失败或者重试
            log.error("不允许重复下单！");
            return;
        }

        try {
            // 5.1.查询订单
            int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            // 5.2.判断是否存在
            if (count > 0) {
                // 用户已经购买过了
                log.error("不允许重复下单！");
                return;
            }

            // 6.扣减库存
            boolean success = seckillVoucherService.update()
                    .setSql("stock = stock - 1") // set stock = stock - 1
                    .eq("voucher_id", voucherId).gt("stock", 0) // where id = ? and stock > 0
                    .update();
            if (!success) {
                // 扣减失败
                log.error("库存不足！");
                return;
            }

            // 7.创建订单
            save(voucherOrder);
        } finally {
            // 释放锁
            redisLock.unlock();
        }
    }
}
/*public Result seckillVoucher(Long voucherId) {
    // 查询优惠券
    SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
    // 判断秒杀是否开始和结束
    if (seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())) {
        // 秒杀尚未开始
        return Result.fail("秒杀尚未开始");
    }
    if (seckillVoucher.getEndTime().isBefore(LocalDateTime.now())) {
        // 秒杀已经结束
        return Result.fail("秒杀已经结束");
    }
    // 判断库存是否充足
    if (seckillVoucher.getStock() < 1) {
        // 库存不足
        return Result.fail("库存不足");
    }
    // 库存充足
    //一人一单
    Long userId = UserHolder.getUser().getId();
    //SimpleRedisLock lock = new SimpleRedisLock("order" + userId, stringRedisTemplate);
    RLock lock = redissonClient.getLock("lock:order:"+userId);
    boolean isLock = lock.tryLock();
    if (!isLock) {
        // 获取锁失败，直接返回失败或者重试
        return Result.fail("不允许重复下单");
    }

    //获取代理对象（避免事务失效）
    try {
        IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
        return proxy.createVoucherOrder(voucherId);

    }  finally {
        lock.unlock();
    }
}*/
